1. Field of the Invention
The present invention pertains to a unique gauge means which is particularly useful in connection with fluid handling apparatus containing fluid having a fluid head. For example, a centrifugal pump generates a dynamic fluid head. A pressurized pipe carrying a liquid also has a fluid head of the hydrostatic type. In any case, the fluid head is functionally related to the density of the fluid and the pressure in the system. The gauge means of the present invention provides a convenient and reliable means of relating three such parameters as fluid head, fluid density, and pressure.
2. Description of the Prior Art
In systems involving three functionally related parameters, such as those listed above, it is often necessary or at least desirable to determine one of the three when the other two are known. In particular, in systems involving pumps, it is often necessary to determine the fluid head. However, since it is difficult to measure this head directly, fluid density and pressure are measured and the head is then calculated using suitable formulae and/or tables. This is time consuming and often difficult for a worker attending the system. Furthermore, errors are often made by the person making the calculations, using the tables, etc.
Another problem frequently experienced in applications in which the three parameters are fluid head, fluid density, and pressure is that workers tend to misunderstand the relationship between the three factors and the nature of the steps which should or should not be taken to place and keep the system in proper working order. In particular, where a pump is being used to direct a fluid from one location to another and thereby generating a fluid head, it is desirable to adjust the pressure and/or density of the fluid until the head reaches a predetermined optimum value. The head should then be kept at this value. As mentioned above, however, fluid head is not ordinarily measured directly. Rather the pressure of the fluid is measured. When the worker sees from the pressure gauge that there has been a change in pressure, he often erroneously assumes that optimum conditions have been lost and attempts to restore the system to its original state by making some change. However, it is often the case that the pressure change which the worker has detected is due to a change in the density of the fluid and that the head has remained constant. If this is the case, he will harm rather than improve the system by making changes aimed at restoring the pressure to its original value.
Thus, there is need not only for a means of determining the value of a parameter such as fluid head without the necessity for consulting tables, making calculations, etc., but also for a means of eliminating common systems operational errors due to misconceptions regarding the nature of the relationship between parameters.